The term 'Oh, go on!' can be expressed in three different ways using crossword solutions. The first is 'pshaw', which is an interjection used to express disbelief or contempt. The second is 'pish', which is a similar interjection used to express disdain or disapproval. The third is 'TUSH', which is an informal way of saying 'BOTTOM' or 'BUTTOCKS'. All three words are used to express the same sentiment of disbelief or dismissal.